Fixes the behaviour of SO_ERROR for tcp sockets where in linux it returns
sk->sk_err and if sk->sk_err is 0 then it returns sk->sk_soft_err. In gVisor TCP
we endpoint.HardError is the equivalent of sk->sk_err and endpoint.LastError
holds soft errors. This change brings this into alignment with Linux such that
both hard/soft errors are cleared when retrieved using getsockopt(.. SO_ERROR)
is called on a socket.
Fixes#3812
PiperOrigin-RevId: 342868552
The active_closefd has to be shutdown only for write,
otherwise the second poll will always return immediately.
The second poll should not be called from a separate thread.
PiperOrigin-RevId: 340319071
Earlier the count was dropped only after calling e.deliverAccepted. This lead to
an issue where there were no connections in SYN-RCVD state for the listening
endpoint but e.synRcvdCount would not be zero because it was being reduced only
when handleSynSegment returned after deliverAccepted returned.
This issue is seen when the Nth SYN for a listen backlog of size N which would
cause the listen backlog to be full gets dropped occasionally. This happens when
the new SYN comes at when the previous completed endpoint has been delivered to
the accept queue but the synRcvdCount hasn't yet been decremented because the
goroutine running handleSynSegment has not yet completed.
PiperOrigin-RevId: 338690646
Accept on gVisor will return an error if a socket in the accept queue was closed
before Accept() was called. Linux will return the new fd even if the returned
socket is already closed by the peer say due to a RST being sent by the peer.
This seems to be intentional in linux more details on the github issue.
Fixes#3780
PiperOrigin-RevId: 329828404
BadSocketPair test will return several errnos (EPREM, ESOCKTNOSUPPORT,
EAFNOSUPPORT) meaning the test is just too specific. Checking the syscall
fails is appropriate.
PiperOrigin-RevId: 328813071
Add tests for socket re-bind/listen of client and server sockets
with the older connection still in TIME_WAIT state and with
SO_REUSEADDR enabled.
PiperOrigin-RevId: 327924702
Netstack's TIME-WAIT state for a TCP socket could be terminated prematurely if
the socket entered TIME-WAIT using shutdown(..., SHUT_RDWR) and then was closed
using close(). This fixes that bug and updates the tests to verify that Netstack
correctly honors TIME-WAIT under such conditions.
Fixes#3106
PiperOrigin-RevId: 326456443
For TCP sockets, SO_REUSEADDR relaxes the rules for binding addresses.
gVisor/netstack already supported a behavior similar to SO_REUSEADDR, but did
not allow disabling it. This change brings the SO_REUSEADDR behavior closer to
the behavior implemented by Linux and adds a new SO_REUSEADDR disabled
behavior. Like Linux, SO_REUSEADDR is now disabled by default.
PiperOrigin-RevId: 317984380
On UDP sockets, SO_REUSEADDR allows multiple sockets to bind to the same
address, but only delivers packets to the most recently bound socket. This
differs from the behavior of SO_REUSEADDR on TCP sockets. SO_REUSEADDR for TCP
sockets will likely need an almost completely independent implementation.
SO_REUSEADDR has some odd interactions with the similar SO_REUSEPORT. These
interactions are tested fairly extensively and all but one particularly odd
one (that honestly seems like a bug) behave the same on gVisor and Linux.
PiperOrigin-RevId: 315844832
When the listening socket is read shutdown, we need to reset all pending
and incoming connections. Ensure that the endpoint is not cleaned up
from the demuxer and subsequent bind to same port does not go through.
PiperOrigin-RevId: 306958038
Attempt to redeliver TCP segments that are enqueued into a closing
TCP endpoint. This was being done for Established endpoints but not
for those that are listening or performing connection handshake.
Fixes#2417
PiperOrigin-RevId: 306598155
The work being done in these threads is not asynchronous with respect to
the test; that is, it is equivalent to issue non-blocking `connect`
calls serially, since the work is done asynchronously with respect to
the caller. Futhermore, this test was added to test closing a listener
with completed but not delivered connections, which never required
threading in the first place.
PiperOrigin-RevId: 306339486
The test is flaky in cooperative S/R mode because TCP timers are not restored
across a S/R. This can cause the TCPLinger2 timer to not fire. This change
disables S/R before setting the TCP_LINGER2 timeout.
PiperOrigin-RevId: 304430536
* Tests are picked for a shard differently. It now picks one test from each
block, instead of picking the whole block. This makes the same kind of tests
spreads across different shards.
* Reduce the number of connect() calls in TCPListenClose.
PiperOrigin-RevId: 293019281
All inbound segments for connections in ESTABLISHED state are delivered to the
endpoint's queue but for every segment delivered we also queue the endpoint for
processing to a selected processor. This ensures that when there are a large
number of connections in ESTABLISHED state the inbound packets are all handled
by a small number of goroutines and significantly reduces the amount of work the
goscheduler has to perform.
We let connections in other states follow the current path where the
endpoint's goroutine directly handles the segments.
Updates #231
PiperOrigin-RevId: 289728325
When listen(2) is called on an unbound socket, the socket is
automatically bound to a random free port with the local address
set to INADDR_ANY.
PiperOrigin-RevId: 286305906
The implementation follows the linux behavior where specifying
a TCP_USER_TIMEOUT will cause the resend timer to honor the
user specified timeout rather than the default rto based timeout.
Further it alters when connections are timedout due to keepalive
failures. It does not alter the behavior of when keepalives are
sent. This is as per the linux behavior.
PiperOrigin-RevId: 285099795
TcpPortReuseMultiThread creates lots of connections which result in
a lot of goroutines in the sentry. This can cause gotsan runs to
take really long and timeout. Increasing listen backlog and
reducing number of connections should help the connections complete
faster as well as reduce the number of goroutines that gotsan needs
to track.
PiperOrigin-RevId: 284046018
The existing tests which are disabled on gVisor are failing because we default
to SO_REUSEADDR being enabled for TCP sockets. Update the test comments.
Also add new tests for enabled SO_REUSEADDR.
PiperOrigin-RevId: 279862275
This change adds explicit support for honoring the 2MSL timeout
for sockets in TIME_WAIT state. It also adds support for the
TCP_LINGER2 option that allows modification of the FIN_WAIT2
state timeout duration for a given socket.
It also adds an option to modify the Stack wide TIME_WAIT timeout
but this is only for testing. On Linux this is fixed at 60s.
Further, we also now correctly process RST's in CLOSE_WAIT and
close the socket similar to linux without moving it to error
state.
We also now handle SYN in ESTABLISHED state as per
RFC5961#section-4.1. Earlier we would just drop these SYNs.
Which can result in some tests that pass on linux to fail on
gVisor.
Netstack now honors TIME_WAIT correctly as well as handles the
following cases correctly.
- TCP RSTs in TIME_WAIT are ignored.
- A duplicate TCP FIN during TIME_WAIT extends the TIME_WAIT
and a dup ACK is sent in response to the FIN as the dup FIN
indicates potential loss of the original final ACK.
- An out of order segment during TIME_WAIT generates a dup ACK.
- A new SYN w/ a sequence number > the highest sequence number
in the previous connection closes the TIME_WAIT early and
opens a new connection.
Further to make the SYN case work correctly the ISN (Initial
Sequence Number) generation for Netstack has been updated to
be as per RFC. Its not a pure random number anymore and follows
the recommendation in https://tools.ietf.org/html/rfc6528#page-3.
The current hash used is not a cryptographically secure hash
function. A separate change will update the hash function used
to Siphash similar to what is used in Linux.
PiperOrigin-RevId: 279106406
This can happen because endpoint.Close() closes the accept channel first and
then drains/resets any accepted but not delivered connections. But there can be
connections that are connected but not delivered to the channel as the channel
was full. But closing the channel can cause these writes to fail with a write to
a closed channel.
The correct solution is to abort any connections in SYN-RCVD state and
drain/abort all completed connections before closing the accept channel.
PiperOrigin-RevId: 261951132
Changes netstack to confirm to current linux behaviour where if the backlog is
full then we drop the SYN and do not send a SYN-ACK. Similarly we allow upto
backlog connections to be in SYN-RCVD state as long as the backlog is not full.
We also now drop a SYN if syn cookies are in use and the backlog for the
listening endpoint is full.
Added new tests to confirm the behaviour.
Also reverted the change to increase the backlog in TcpPortReuseMultiThread
syscall test.
Fixes#236
PiperOrigin-RevId: 252500462
Fixed a small logic error that broke proper accounting of MultiPortEndpoints.
PiperOrigin-RevId: 246502126
Change-Id: I1a7d6ea134f811612e545676212899a3707bc2c2
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
This option allows multiple sockets to be bound to the same port.
Incoming packets are distributed to sockets using a hash based on source and
destination addresses. This means that all packets from one sender will be
received by the same server socket.
PiperOrigin-RevId: 227153413
Change-Id: I59b6edda9c2209d5b8968671e9129adb675920cf
